Four score and seven years ago, Ford Motor Co. brought to St. Paul a new assembly plant, conceived in the brain of Henry Ford and dedicated to the proposition that it's cheaper to build cars near a major river you can dam to generate your own electricity. Or something like that.

Now the last Ranger pickup has rolled off the line, and St. Paul has approved the company's plans to turn the 122-acre Highland Park industrial site into developable prairie by the end of the decade.

And Brian McMahon thinks it's a shame that nothing of the old plant -- a Twin Cities landmark for nearly nine decades -- is planned for survival.

"The richest types of development show some sense of place," said McMahon, who leads University United, a community group promoting transit-oriented development, and has a book in the works on the Ford plant's history.

"Otherwise, every other development from here to Juneau, Alaska, would be the same."

Barring glitches, the plant's major structures -- the 1920s-era main assembly building, the paint building and a modern training center -- will be gone by this time next year.

The company tried for years to interest developers or investors in the property, Ford site manager Mike Hogan said, but "no viable business use or buyer ever emerged."

Ford's goal now is to make the site as saleable as possible for developments ranging from homes to businesses, perhaps even light manufacturing. Its demolition plans, unanimously approved last week by the St. Paul Planning Commission, will take at least three years and may not be completed until 2019.

The result will be a tract of grassy riverfront, a blank swath in the midst of one of St. Paul's most desirable neighborhoods to draw all sorts of developers.

McMahon thinks he has a better idea. He said the training center, with its robotics bay, classrooms, labs and auditorium, could be an enticement to companies to relocate to the Ford site. Then a small part of the assembly building connected to the training center could be saved for industrial use while also serving as a living fragment of the plant's past.

The training center opened in 1999 with $5 million from the state and contributions from St. Paul, Ford and the United Auto Workers. "It really adds value to the development," he said.

But Minnesota State Colleges and Universities has passed on the training center. Other possibilities have faded.

And while Ford isn't opposed to some kind of commemoration of the site -- it plans to salvage part of the historic facade, exterior lamps and some inside fixtures for future buildings on the site -- Hogan said there's little time left to do much more.

"We tried to flush out potential new uses and it hasn't presented itself to this point," Hogan said. "So I'm pessimistic that something would present itself in the course of 2013."

McMahon shakes his head. If the training center comes down, it will be a wasted investment, he said. And a plaque on the site saying that Ford once built cars here just won't do it.

"The way it's going now, there will be virtually nothing left that will make any acknowledgements of the important role Ford played. That's really incredible," he said.